Colonnade Aluminium Round Downpipe With Cast Collar

The Colonnade range of Circular Rainwater Downpipes are available with a cast connector in 63mm, 76mm and 101mm profiles and lengths ranging from 0.5 to 3.0 metres in mill or polyester powder coating (PPC) finish.


Round downpipe formed from extruded 6060 T4 aluminium in conjunction with a LM27 Cast Collar in various sizes (63mm, 76mm & 101mm) & supplied with a complete range of accessories ie offsets, bends, shoes, pipe clips.

How Do I Install Aliminium Cast Collared Downpipes

Ensure vertical alignment between drain & gutter outlet.
Collars to be fixed with plastic wall plugs & No.14 x 38mm st.stl screws (dependant on substrate).
Joints to be made up of Ø6mm backing foam caulked into the joint & finished off with sealant to acceptable standard.
Typical section through collar

We advise that you ensure the fixing background is in good condition and will support the downpipe and that there are sufficient clips/brackets in place to secure the load.
ARP manufactures 3 different pipe systems (Swaged, Flush joint and Cast Collared) and the below instructions are applicable to all systems unless specifically mentioned.
When fitting Colonnade downpipes, start from the outlet and work towards the gully. Make sure you have the right combination of offsets/bends/branches and pipe to complete the installation.

Maximum fixing centres is 2 metres – using correct stainless-steel fixings and plugs for the substrate being fitted to.

1-Ensure vertical alignment between drain and pipe socket prior to installation.


2-Sealant can be applied to the inside of the pipe socket prior to installation.

Swaged and flush joint downpipes should have sealant applied to the socket prior to installation.

Cast Collared can be sealed after fitment.

When fitting flush joint downpipe, sealant can also be applied to the inside of the clip to assist in supporting the pipe.

3-Ensure vertical alignment between drain and gutter outlet.

Adjust the offset to suit the projection.

Place the offset in position from the outlet and fix the first pipe into place, thus holding the offset in position.

4- Additional pipe clips should be fitted at 2m maximum intervals.
Carry on installing pipes in this fashion until reaching the drain.
Clips to be fixed with plastic wall plugs and stainless-steel screws of a size suitable for the substrate.

5- A shoe, drain adaptor or offset may be required to terminate the pipe work into the gully.

6-As per local building regulations, if a shoe is not installed access pipes should be fitted and positioned to give suitable rodding access as required.

Any Cut Lengths Should be de-burred and touched up with touch up paint supplied prior to installation for more information or further assistance, please contact us.
Where required, any use of sealant must not be carried out in wet weather or in temperatures below 5ºC or above 50ºC. All joint surfaces must be perfectly clean and dry. Only a low modulus sealant (ARP Arbosil 1096) must be used to prevent early failure.

It is important that all fixings are suitable for both the substrate and the load. They must therefore be of the appropriate size and of a compatible material to ensure no electrolytic corrosion occurs. ARP recommends that stainless steel (preferably austenitic) screws must be used to fix downpipes or associated components.

Composition & Manufacture:

‘Colonnade’ downpipes are manufactured from Aluminium alloy 6060 T4 to BS1474: 1972 & the product complies to, or exceeds all relevant standards.Cast Collars are manufactured from LM27 aluminium. Fittings for the downpipes are formed using fabrication methods involving cut,mitre & welding techniques using specially made jig & forming tools.


Mill Finish Aluminium or Polyester Powder Coated to a range of BS or RAL Colours.

Model Specification

ARP heavy grade ‘Colonnade’ Cast Eared Downpipes & fittings to BS 2997 (EN612) using 6060 T4 grade extruded aluminium in accordance with BS 1474: 1974. Profile to be Round, size Ø63mm (1.6mm), Ø76mm(1.6mm), Ø101mm (1.6mm).
Materials to have factory applied Polyester Powder Coat to all significant surfaces in accordance with BS EN 122026 Matt/Satin/Gloss* finish, or alternatively plain aluminium Mill Finish. All to be supplied by Aluminium Roofline Products Ltd, Unit 2, Vitruvius Way, Meridian Business Park, Braunstone, Leicester LE19 1WA. Tel 0116 2894400 Fax 0116 2894433.
Joints to be sealed by application of backing foam & Arbosil 1096 Low Modulus Silicone Sealant & fastened by No.14 x 38mm (dependant on substrate) stainless steel screws, in accordance with the manufacturer’s specification & guidelines. Downpipes to be fixed at 2m centres maximum with supplementary brackets at or near fittings.

ARP Round Aluminium Cast Collar Downpipe Technical Guide